許多人長途旅行經(jīng)歷時差變化后都有疲累感覺，但英國研究人員發(fā)現(xiàn),，賽馬在經(jīng)歷時差之后運動能力反而增強,，能夠全速奔跑的時間變得更長。
英國布里斯托爾大學(xué)等機構(gòu)的研究人員在《神經(jīng)內(nèi)分泌學(xué)期刊》上報告說,，他們針對一些受過良好訓(xùn)練的賽馬進行了實驗,。這些賽馬被置于光線受控制的房間中，先進行3個月的正常訓(xùn)練,，其間光線變化遵循正常的白晝黑夜循環(huán),。隨后研究人員通過改變燈光，營造出時間快了7個小時的環(huán)境,，讓這些賽馬經(jīng)歷時差變化,。
結(jié)果顯示，與人類在經(jīng)歷時差后運動能力往往下降不同,，這些賽馬出現(xiàn)運動能力上升的現(xiàn)象,。以在表現(xiàn)出疲勞前能夠全速奔跑的時間為例，賽馬在經(jīng)歷時差后全速奔跑的時間延長了25秒,。
研究人員多明戈·托爾托內(nèi)塞說,，這可能是因為賽馬和人適應(yīng)時差的方式不同。人體生物鐘的慣性較強,，當(dāng)生物鐘與外部時間不一致時,，身體需要時間來慢慢適應(yīng)。而賽馬對光線非常敏感,，一旦光線發(fā)生變化,，身體內(nèi)分泌系統(tǒng)很快隨之變化,，來幫助它們適應(yīng)環(huán)境的改變，運動能力提高則是內(nèi)分泌變化的一個意外產(chǎn)物,。（生物谷 Bioon.com）
doi:10.1111/j.1365-2826.2011.02222.x
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PMID:
Experimental Jetlag Disrupts Circadian Clock Genes but Improves Performance in Racehorses after Light Dependent Rapid Resetting of Neuroendocrine Systems and the Rest‐Activity Cycle
Tortonese, Domingo J.; Preedy, Danielle F.; Hesketh, Shirley A.; Webb, Hayden N.; Wilkinson, Elizabeth S.; Allen, William R.; Fuller, Catherine J.; Townsend, Julie; Short, Roger V.
Abrupt alterations in the 24-h light:dark cycle, such as those resulting from transmeridian air travel, disrupt circadian biological rhythms in humans with detrimental consequences on cognitive and physical performance. In the current study, a jetlag-simulated phase shift in photoperiod temporally impaired circadian peaks of peripheral clock gene expression in racehorses, but acutely enhanced athletic performance without causing stress. Indices of aerobic and anaerobic capacities were significantly increased by a phase-advance, enabling prolonged physical activity before fatigue occurred. This was accompanied by rapid re-entrainment of the molecular clockwork and the circadian pattern of melatonin, with no disturbance of the adrenal cortical axis, but a timely rise in prolactin, a hormone known to target organs critical for physical performance. Subsequent studies showed that, unlike the circadian pattern of melatonin, and contrary to other species, the daily rhythm of locomotor activity was completely eliminated under constant darkness, but it was restored immediately upon the reintroduction of a light:dark cycle. Resetting of the rhythm of locomotion was remarkably fast, revealing a rapid mechanism of adaptation and a species dependency on light exposure for the expression of daily diurnal activity. These results show that horses are exquisitely sensitive to sudden changes in photoperiod and that, unlike humans, can benefit from them; this appears to arise from powerful effects of light underlying a fast and advantageous process of adjustment to the phase shift.
